Water level indicator for floating dry docks



F. R. HARRIS WATER LEVEL INDICATOR FOR FLOATING DRY DOCKS May 24, 1949.

3 sheets-sheet' 1 Filed Nov. 21, 1945 m m N m E E .w M, mw N N N i N a V MAJ is---) EL 1H f I ||J n 1| I|..| u UEWi N2 j .mswwhm l..

May 24, 1949. F. R. HARRIS l l2,470,85()

WATER LEVEL INDICATOR FOR FLOATING ERY DOCKS Filed NOV. 21, 1945 3 Sheets-Sheet' 2 l INVENTOR. /Trefienc filly/'15' Hrw/amy l May l24 1949. 4F. R. HARRIS 2,470,850

WATER LEVEL INDICATOR FOR FLOATING DRY DOCKS Filed Nov, 21, 1945 3 sheeis-sheet 5 FTW;

INVENTOR.

f affair/vm Fminz f?. af/s BY Patented May 24, 1949 UNITED STATES Frederic R. Harris, New York, N. Y.

Application November 21, 1945, Serial No. 630,006

l1 Claims. l-

This invention relates to water level indicators, and more particularly to apparatus for revealing quickly, and in clear and unmistakable fashion, the inside. and outside draft at various parts of a: floating drydock.

The conventional floating drydock has a pontoon hull and side walls; and its interior is divided into compartments arranged along the sides, each compartment at one side being opposed to a similar compartment at the other. Water is admitted to said compartments, and discharged therefrom as conditions demand. En practice whenever a oating dock is operated to raise a ship out of water, any excessive stresses in the structure of either the ship or the drydock must be avoided. To this end the buoyancy lift of any transverse section of the dock must approximately balance the. vertical load imposed upon that particular section. As the weight of the dock is essentially uniform, throughout its length, the imposed load on any part of the dock is determined by the Weight of the part oi the ship immediately above the aforesaid part or section of the dock. Any diierence between this weight and the buoyancy of such part of the dock is balanced by the weight of the water introduced into the ballast compartments. The most convenient Way to measure the Weight of the water in any compartment of the dock is to ascertain its depth.

For this purpose water level indicators are put upat a central station, such as the control house ofthe dock, and connected to register the depth of'water at all necessary places. Such indicators may be of the dial and movable pointer type; but indicating units such as vertical tubes containing a liquid and working on the principle of the manometer, are more advantageous and desir able. The height of the contained liquid tells the water depth, and a suitable scale gives the readingrin feet.

The preferred method of measuring and indicating water depth in any part of the dock is based on the principle of transmitting the pressure due to the static head of the Water. This pressure is given by a column of mercury in a tube orl other vessel of glass, or the like transparent material. The depth of water in feet is made known on a scale beside the tube.

It is an important object of this invention to provide a water level indicator for a floating drydock, comprising a suitable number of liquid enclosing tubes in a novel combination that will quickly and infallibly make apparent to the eye the level ofV the Water at each of the separate points, inside and outside the dock, wherev the depth of the water must be watched. The ape-- generally installed parallel to the main; the dock. The tubeslvare paratus is or longitudinal axis of isposed in pairs, side by side, half the me'lfribc'rsL of such pairs being each connectedl singly'and separately to the compartments in succession:

along one side of the dock, andthe other membersY similarly to the successive compartments; along! the opposite side; in the same order' asl the-ar;V

rangement of the compartments themselves at`r the sides of the dock. The different memberslr olfv the pairs thus make two interspersed butwelldel iined sets; and all form a single largerow'or' group. At the extreme ends of theY row are lli-l cated additional tubes for disclosingl the out-4 side draft at the opposite ends of thedock the tubes are sufciently close together tobe' witrl in the eld of View. Each tubev is conspicuously' v marked with the number of' its associated` come partment and the' two setsoi' tubes, one. .set-ion each row of compartments along the' twol'sidesiof the dock, are distinguished from one another by different colors.

By this construction the attendant'v can' see at a glance what are the water levels atall neces---lv sary points for any stage in sinking; 'He' can also tell by any difference in they heights; of the liquid in the two sets of tubes, ifv and in' what? degree the dock is listing sidewise; and; ii the tops of the liquid in the tubes of either' seti slio'w'- a gradient along the row from endto end thereof, to what extent one end' of the dockma'yb'e higher' in the water than the other; and thus ari-"ive4 at whatever amount of trim of thedock maybe needed.

by means of colored pointers on the' scales@ op#- posite each of the tubes; for example, the necessary Water level in all compartments at stageff1 can be marked by appropriately 'located redpcinti#m ers at all gauges at stage 2 by white pain-tw ers, etc. can be carried out by so working the pumpsthat the water level in each compartment willl be at the correct height for each stage of' the operation"- in full accordance with the pumping plan.`

Furthermore, if it is desired that tli'e shall have a trim at one end, cords are* putv along thetops of the' liquid in the tubes to 'delineate the In this manner' the docking operation:

3 slope of the liquid in the units. trim is then easily perceived.

The nature of the invention is fully described in the accompanying specication and illustrated on the drawings, but the right is reserved to make changes in structural details without alteration of essential characteristics, as set forth in the appended claims:

On said drawings,

Figure 1 shows in outline an indicating apparatus according to this invention.

Figure 2 is a front view of a part thereof on an enlarged scale.

Figure 3 is a transverse vertical section showing the method of mounting and the operating connections for individual indicating units.

Figure 4 is a horizontal section about on the line 4 4 of Figure 3.

Figures 5, 6, '7 and 8 present details; and

Figure 9 is a diagram of the operating connections from the apparatus to the various compartments in the hull of the dock.

The same numerals identify the same parts throughout.

The invention comprises a vertical panel or control board properly mounted on a support having the form of a framework consisting of vertical bars I, connected by transverse horizontal bars 2 and horizontal bars 3 extending from the front to the back of the framework. Whereever necessary the front and rear of the framework may be covered by steel plates 4. In the framework are mounted sections of berboard 5 or the like with intervening spaces for two sets of transparent tubes 6 and 6a. units of the two sets are interspersed because the tubes 6 and 6a alternate along the whole length of the row. The tubes are al1 alike and have numbers as illustrated in Figures 1 and 9. For example, the even numbers on the panel are below the tubes 6; and an odd number on the panel is at the lower end of each of the remaining tubes 6a. The framework may be of any desired construction or design and the details thereof are not part of this invention.

The tubes are of course Vertical and are placed side by side and each successive couple of tubes 6 Aand 6a can be regarded as a separate pair.

The number of each of the tubes on the panel corresponds to the compartment of the dock with which it is connected. Figure 9 represents diagrammatically the plan of the hull of the dock in which the compartments on one side bear odd numbers, from one end of the dock to the other; and the compartments on the other side, in the same order, bear even numbers. The tubes 6a, for instance, having odd numbers at their lower ends, all communicate separately and singly with the compartments having odd numbers, and the alternate tubes 6 having the even numbers communicate in the same manner with the opposite row of compartments having even numbers, on the other side of the dock.

On top of each tube is a reservoir 'I and at the bottom a packing gland 3, which connects the tube to a length of piping 9 extending downward. The lower extremity of pipe 9 is connected with another vertical length of piping I0 by means of a short horizontal piece of piping I I. 'I'he sections of pipe 9, IB and I i and each of the tubes constitute a manometer; and a liquid, such as mercury, in the tubes will of course rise or fall according to the pressure on one end thereor, in the tube I0.

The upper extremity of each length of piping The amount of The tubes or III is connected by a piece of piping I 0 to the casing of a four-way valve I2. From the casing of each valve I2 a pipe I3 leads downward to the dock compartment which the particular tube serves, and the top of the casing of each valve I 2 is connected to an air header I4 by a pipe I 5. Each valve I 2 is controlled by a knob I6 on the face of the panel comprising the sections 5, this knob being connected by a stem to the body of the valve inside the casing I2. In one position the pipes I0 and I3 are connected so that the depth of the Water in the particular compartment is indicated by the height of the liquid in the tube 6 or 6a. In another position the pipe I0 is cut oil by the valve from the pipe I 3, and the pipe I3 is put into communication with the pipe I5. Then by means of the compressed air in the reservoir connected to the header Ill, each of the lines of pipe I 3 can be blown out when necessary. The conditions under which the knobs I5 are operated to throw the valves into position to blow out the pipes I 3 need not be detailed herein. The manner in which the pressure is maintained in the piping I3 and caused to operate the mercury in tubes is also not a part of this invention; and any suitable method or devices for establishing the necessary pressure in the pipes I3 and all the manometers may be adopted.

The liquid in the various tubes is pushed up in these tubes by pressure in the pi es I3. These pipes, as stated above, project downward into the various compartments of the dock. The more Water in the compartments, the farther down below the level thereof are the lower ends of the tubes I3. The pressure of water below the surface, as is well known, varies directly with increasing depth. The deeper the water in the compartments the more it will rise in the tubes I3 above the lower ends and the greater will be the pressure in the tubes I3 and tubes 5 and 6a; with the result that the level of the liquid in the tubes, through the action of the pressure in the tubes I3, indicates the of the Water in the compartments of the dock.

My invention relates primarily to the arrangement of the tubes and the visual effect which these tubes and the liquid therein are capable of giving. At the right of each of the tubes G and forming part of the iiberboard front of the panel is a vertical strip I', the face of which bears a scale with graduations indicating depth of water in feet according to the height which the Column of liquid reaches in the tube next to said scale; see Figure 2, and similar strips Ila provide scales for the tubes or units Also beside each scale is a Vertical groove i8 in the berboard panel to receive an element or pointer I9. Each pointer can slide up and down its slot I3, and can be moved into a pesition i'iush with the top of the column of liquid in the adjacent tube. To distinguish the scales of the tubes for the starboard compartments from the snai-es for the tubes of the port compartments, the strips I7 and I'ia may be of diiierent colors. @ne set may be green, for example, and the other brown, or any other easily distinguishable colors may be adopted. Then the liquid in the tubes adiacent the brown scales will indicate the level. of thc water in the compartments on the port side and the liquid in the tubes adjacent the scales of a different color will similarly indicate the depth of the water in the compartments on the starboard side. The condition of the various compartments of the dock and the height of the water level ineach .will thus beinf al-libly indicated tothe observer, without vrisk -of error.

. At .theends of the rows of :tubes @and-da are additional tubes :besides which .are simile r scale bearing parts Il'. There willalso be slots i8 beside each of the scale bearingfparts l-'l for pointers I9. The height of the liquid inthe tubes B'fshows theoutside Vdraft-at the two ends of the dock,y and the scales show'the same in feet. The knobs for the tubes Vl are therefore designated by the letter D. There vmay be a pair -of tubes 6 ateach end of the panel, one foreach .corner of the dockv at that end, although only one is shown-inthe drawings. Also, an additional vertical groove I8 is provided at the two ends oi the control board. Each of these grooves l receives a Ipair of zelements or markers lrfi; Thus, there will be Ytwo Imarkers at the left-end Iofthe row of tubes and two at the right-end. In preparing the empty dock to receive or discharge a ship with a list lor a trim `(vor both a list 'and trim) it is desirable to establish the depths of ballast `water in the several compartments at diierent predetermined levels. To accomplish this easily, at the Ileft end a marker will be adjusted -to the desired height oi the level oi the liquid-in the adjacent -tube'a of the set for the compartments at one side of the dock; .and at the opposite end of the control board a marker will be set at the desired height of the level in the last tube 8a for the same side of the dock. These two markers will be joined by a wire or string yindica-ted at v22, which will run 'along the tops of the mercury columns in the tubes 5a.. The same procedure will 'be vfollowed forthe other set of tubes 6; a string 23' is stretched from the other two markers l2l, one at each end or" panel, to mark the level of the mercury desired in the tubes 6, and the difference between heights of these two strings will be a `measure of the difference in ballast on the two sides vof the dock and will therefore `indicate `an' amount of list. At the same time, the slope or gradient of. these two cords 4or strings will indicate the diierence in ballast weight distributed along the i axis of the dock and will therefore indicate the amount of trim. In this way, the condition of the ballast water at all points in the doel; will always bevmade clear.

In Figure 2 several pointers i9 are shown for each of the scales. The pointers are all of different. colors, each set of one color showing the desired "level of water in the dock compartments for one stage of operation as described above. It

is understood that :several such pointers le of diierent -colors are inserted in the grooves i8 of every scale l-1 and Ila, although, for convenience and `clearness the pointers .do not appear in l g ure 1. The same number of diferent coiored pointers may also be used with the end tubes il.

.If the dock needs trim at one end, the operation is conductedaccordingly till the strings '2 and 23 show the gradient desired. If the dock. is to have a list, allcompartments on one side of the dock are flooded with more water than tne compartments on the other side. This dilerence in the height ofthe mercury columns in the two sets of tubes indicated by the two strings 22 and 23 stretched across the front of the board will show the estimated depths of ballast water required to produce the desired list. The depths of ballast water can be adjusted till the desired list is actually reached.

Besides each of the tubes 6' is an additional scale l'lb, with a groove I8 and pointer i9 to show the draftover the. -keel blocks `on:lthe'fdeck of .the dock to engage theshipsfbottom. This scale may be vertically adjustable-:byfmeans 'df a screw-and-slot mounting I2Q.

It is understood, of course,..that, Ain' Figureei, the parts 6 anda show Vthe mercury columnsuin the various tubes, rather thany the ytubes theme selves; a full appearance of. the tubes.y in :this View being unnecessary. In this figure, the'fconnections including pipes 13 for thertube'sr' .are included at the ends.

My invention can of course fbe used 1in various constructions besides floating dry 'docks towindicate the level of liquid in 'diferent scomparti-'- ments or parts.

Having described my invention, what lzclaiinais:

l. Indicatork apparatus for a floatingfdry dock having a hull with interior kcompartments along. both sidesyeach compartment on 'oneisideibeing opposed to a compartment 'on the otheryaa; row of tubes each containing a liquid, a supportior holding said tubes relatively-close together ini/one iield of view; said tubes being mountedfsrde'lby side in pairs, and connections `for transmitting. pressure to the liquid in each tube, ksaid comico-- tions extending singly and separately :Erornfi'o'ne tube of each pair to thecompartmentsrinrsuccesf-l sion at one side of the #dockand fvfrornfzthecother tube of each pair in the like order andrsuccession: to the compartments along the other'fsidexof 'the dock.

2. Indicator apparatus for a vfloating''clryfdcclz having a hull with interior compartments :along both sides, each compartmentonl oneiside'bein'g opposed to a compartment on the other: la row of tubes each lcontaining a liquid, a supportnfor holding said tubes relatively close 'together lin one field of View; said tubes being mounted-side by side in pairs, connections for transmitting pres-i sure to the liquid in each Vtube,said:connections extending singly and separately from one `.tube of each pair to the compartments in succession at one side of the dock and `from Ithe other tube of each pair in the like order `and succession toy the compartments along vthe other side fof, "the dock, and vertically movable markers on saidy support adjacent the `ends Yof `said row.

3. Indicator apparatus for 'a oating-'dryfdock having a hull with interior compartments,1along both sides, each compartment on'onelside being opposed to a compartment -on the iother; rowf of tubes each containing a liquid, 'ar-supporttior holding said tubes relativelyclosetogether incheeld of View; said tubes being mountedzsidewby side in pairs, and connections lfor transmitting pressure to the liquid in'each tube, said connes--v tions extending singly and separately'from' one tube of each pair to the compartments insucces-v sion at one side of the dock'and vvfrom tlziefot'lsrerv tube of each pair in the like order'and'successionA to the compartments along the other side of .thef dock, said support comprising scale-bearingaparts adjacent each tube and verticalslots iniproxiin-ityf to said parts, and movable pointers =in fthe* slots to register with the tops 'of yther'liquid inf-said' tubes.

4. Indicator apparatus .for a 'floating :dryidool:Y

having a hull with interior compartments, a group of tubes each containing a liquid, a support for mounting said tubes relatively close together in one field of View, connections for transmitting pressure to the liquid in each tube, and extending singly and separately from each tube to one of said compartments, vertically movable markers on the support adjacent the extermities 0f said group and additional liquid-containing tubes adjacent said extremities to measure the outside draft of the ends of the dock.

5. Indicator apparatus for a oating dry doel: having a hull with interior compartments alone both sides, each compartment on one side be' opposed to a compartment on the other; a ro f tubes each containing a liquid, a support for holding said tubes relatively close together in one field of view; said tubes being mounted side by side in pairs, connections for transmitting pressure to the liquid in each tube, said connections extending singly and separately from one tube of each pair to the compartments in succession at one side of the dock and from the other tube of each pair in the like order and succession to the compartments along the other side of the dock and additional liquid-containing tubes at the ends of said row to measure the outside draft at the ends of said dock.

6. Indicator apparatus for a floating dry decir having a hull with interior compartments along both sides, each -compartment on one side b i, opposed to a compartment on the other; a row of tubes each containing a liquid, a support for holding said tubes relatively close 'together in one field of View; said tubes being mounted side by side in pairs, connections for transmitting pressure to the liquid in each tube, said connections extending singly and separately from one of each pair to the compartments in succession at one side of the dock and from the other tube of each pair in the like order and succession to the compartments along the other side or". the dock, vertically movable markers at the extremities of said roW, and additional liquidecontaining tubes adjacent said extremities to measure the outside draft at the ends oi the dock.

7. Indicator apparatus for a floating dry doeii having a hull with interior compartments e-o both sides, each compartment on one side b opposed to a compartment on the other; a row of tubes each containing a liquid, a support for holding said tubes relatively close together in one eld of view; said tubes being mounted s by side in pairs, connections for transmitting pressure to the liquid in each tube, said connections extending singly and separately from one tube of each pair to the compartments in succession at one side of the dock and from the other tube of each pair in the like order and succession to the compartments along the other side of the dock, said support comprising scalebearing parts adjacent each tube and vertical slots in proximity to said parts, with movabie pointers in said slots to register with the tops of the liquid in said tubes, and additional liquidcontaining tubes adjacent said extremities to measure the outside draft at the ends oi the dock.

8. Indicator apparatus for a floating dry dock having a hull with interior compartments along both sides, each compartment on one side being opposed to a compartment on the other, a row of tubes each containing a liquid, a support for holding said tubes relatively close together in one eld of view, said tubes being mounted side by side in pairs, said tubes thus being divided into two sets, one of which embraces one member of each pair and the other the remaining members, connections for transmitting pressure to each tube, said connections extending singly and separately from one tube of each pair to the compartments in succession at one side of the dock and from the other tube of each pair in the like order and succession to the compartments along the other side of the dock, said support having vertical slots at each end oi the row of tubes, and a movable marker for each set of tubes in each of said slots, the line across the support between the markers of each set registering with the top of the liquid in the tubes thereof.

9. Indicator apparatus for a floating dry dock having a hull with interior compartments, according to claim 8, which also has additional liquid-containing tubes and scale-bearing parts at the extremities of said row to measure the outside draft at the ends of the dock.

10. Indicator apparatus for a floating dry dock having a hull with interior compartments, a group of tubes each containing a liquid, a support for mounting said tubes relatively close together in one eld of View, and connections for transmitting pressure to the liquid in each tube, and extending singly and separately from each tube to one of said compartments, said apparatus having vertical markers on the support at the ends of the group, the positions of the markers showing the level of the tops of the liquid in said tubes.

11. Indicator apparatus for a floating dry dock having a hull with interior compartments, a group of tubes each containing a liquid, mounted relatively close together in one ield of view, connections for transmitting pressure to the liquid in each tube and extending separately and singly from each tube to one of said compartments and a set of markers for each tube, the markers of each set being of different appearance and the corresponding markers of the sets being of the same appearance, so that the corresponding markers can be placed in position to designate the water levels in the compartments at various stages in the docking operation.

FREDERIC R. HARRIS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 685,164 Morris Oct. 22, 1901 1,333,580 Ximenez Mar. 9, 1920 1,428,363 Dreiske Sept. 5, 1922 1,917,846 Klopsteg July 11, 1933 2,379,585 Crandall July 3, 1945 2,379,902 Harris July 10, 1945 FOREIGN PATENTS Number Country Date 322,471 Germany June 30, 1920 

